This is a research and development effort aimed at applying the concept of condensation enlargement to the problem of controlling respirable coal dust in underground mines. A laboratory prototype dust collection syystem will be designed, contructed, and evaluated. This system will consist of a parallel-plate condensation conditioner, inside of which the dust particles will nucleate water droplets and grow to collectable sizes, followed by a water spray. Design calculations are presented here which indicate that the basic design is feasible in terms of size, air handling capacity, dust load capacity, and water and energy consumption. The proposed concept has advantages of very high efficiency, quietness of operation, no high voltages or potential for sparking, low water consumption, moderate energy consumption, and simplicity. The design will be based on data obtained previously in this laboratory on nucleation and water droplet growth on coal dust. The evaluation experiments will consist of measurements of output droplet sizes, coal dust transmission, and water and energy consumption. During the evaluation, design parameters will be optimized for application to a full-scale model to be built and tested in the later phases of the program. The ultimate objective of the research is the development of a dust collection system having the potential for greatly decreasing respirable dust concentrations in coal mines.